p-INVERT of the positive integers, where p(S) = 1 - 4*S^2.

Terms

a(0) =0a(1) =4a(2) =16a(3) =56a(4) =208a(5) =780a(6) =2912a(7) =10864a(8) =40544a(9) =151316a(10) =564720a(11) =2107560a(12) =7865520a(13) =29354524a(14) =109552576a(15) =408855776a(16) =1525870528a(17) =5694626340a(18) =21252634832a(19) =79315912984a(20) =296011017104